This circuit generates sinusoidal signals that depend on the input oscillator. The circuit is from a Radio Elecrtronics from April 1988. The signals are in the range of a few hundred kilohertz.
This National Semiconductor circuit appears elsewhere on this site. The circuit must be powered by...
In this circuit the frequency is determined by the coil and the variable capacitor. Transistors like the...
This circuit is from old American documentation, but the transistor used is still very common...